Fuse



Nov. 6, 1934. A. G. STEINMAYER Er Al.

FUSE

Filed oct. 20, 1932 (Ittorneg df/m k VZ 1w Patented Nov. 6, 1934 UNTEDSTATES PlirENr orrics waukee, Wis., assignors to Line Material Company,South Milwaukee, Wis., a corporation of Delaware Application October 20,1932, Serial No. 638,676

Claims.

This invention relates to fuses and is particularly directed to anexpulsion type of fuse.

In expulsion type fuses where the fuse cartridge is housed with the openend of the cartridge ad- 5 jacent the lower portion of the housing, ithas been found diicult to prevent gases entering through the lowerportion of the housing. These gases are highly conducting and it is verydesirable to keep them from entering the housing at the time of theexpulsion of the fuse.

Objects of this invention are to provide a novel type of expulsion fusein which means are provided in the form of abarrier or shield closelyadjacent the lower portion of the fuse cartridge and cooperating withthe opening in the housing so that the gases are prevented from enteringthe housing, but instead in which the barrier itself materially reducesthe possibility of the reversal of the flow of the gases adjacent theopen end of the cartridge, thereby greatly increasing the safe rupturingcapacity of the fuse.

In greater detail, further objects of this invention are to provide anexpulsion fuse in which the barrier is located very close to the extremeopen end of the fuse so that the gases do not have an opportunity tochange their direction adjacent this open end, in which there are noslots which provide free access of the gases to the inner portion of thehousing adjacent the end of the tube, in which the cartridge is slightlyinset with reference to the bottom of the housing so as to house orprotect the looped end of the fuse to avoid accidental contacttherewith, and in which the bottom of the box or housing substantiallyencircles the barrier at the end of the fuse tube.

Embodiments of the invention are shown in the accompanying drawing, in`which:

Figure 1 is a longitudinal sectional view through the device, with partsbroken away.

Figure 2 is a sectional view on the line 2-2 of Figure 1.

Figure 3 is a fragmentary sectional view of a mcdied form.

Figure 4 is a view corresponding to Figure 3 of a further modied form.

Referring to the drawing, it will be seen that the housing comprises abox l formed of porcelain or other suitable material. This box isprovided with a hingedly mounted cover 2 in accordance with the usualconstruction. The body portion is provided with an intermediate notchedbarrier 3 within the notch of which the fuse cartridge 4 is positionedwhen the cover is closed.

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(Cl. 20G-127) The fuse cartridge is provided with an upper contact 5 anda lower contact 6, the upper contact being provided with a clamping cap7 to secure the upper end of the fuse link 8. The lower end of the fuselink is looped around the lower end of the cartridge and around thebarrier 9 and secured by clamping means, such as the thumb nut l0, tothe lower contact 6.

The cover or door 2 is provided with a looped or eyelet portion 11 intowhich a small hook 12 carried by the upper Contact fits, preferably ayielding spring nger 13 being clamped to the member 11 and yieldinglyengaging the nger 12to prevent radio interference.

The lower end'of the fuse cartridge is received between spring fingers14 carried by the door, and the lower contact 6 is provided with ashouldered portion l5 which rests upon a metal support 16 secured to thedoor. A small leaf spring or resilient Contact member 17 is carried bythe support in order to insure contact and prevent radio interference,although this feature forms no portion of the present invention.

It is to be distinctly understood that any other suitable means could beemployed for removably securing the fuse cartridge to the door, as thespecific details of this securing means forms no portion of thisinvention.

The body portion is provided with a lower terminal member 13 equippedwith spaced spring fingers 19 which receive the lower contact 6 when thedoor is closed. The body portion is also provided with an upper terminalmember 20 similarly equipped with spaced spring fingers 2l which receivethe upper contact 5 when the door is closed.

Attention is directed to the barrier 9 shown in Figures 1 and 2. Thisbarrier or shield may be circular, as indicated in Figure 2, and iscarried at the bottom end of the fuse cartridge or tube Li. The fuselink 8v is looped downwardly around the bottom end of the fuse cartridge4 and around the barrier 9. The body portion 1 is provided with a cutout22 and the bottom portion of the door is provided with a cutout 23which, as may be seen from Figure 2, jointly form a. substantiallycircular aperture within which the barrier 9 is positioned. The barrier9 substantially lls the lower opening in the housing, as is obvious fromFigure 2, and is located closely adjacent the lower end of the housingso as to prevent the reverse ilow of gases upwardly into the housing.

Although the exact theory of operation of the device is not fully knownat present, it is believed that the barrier located very closelyadjacent and, in the form shown, at the lower end of the fuse cartridge,prevents the gases from starting backwardly adjacent the open end of thecartridge and consequently the gases do not reverse their direction offlow but are completely discharged downwardly from the free end of thecartridge.

The barrier may completely fill and may seal the lower opening of thehousing. For example,

as shown in Figure 3, the door 24 is provided with a tapered opening 25Within which a yielding tapered, cone-shaped barrier 26 carried by thefuse cartridge 4 fits in a substantially gas-tight manner. If desired,the barrier 2 6 or shield may be formed of rubber or other yieldingmaterial. In this form of thev invention the opening 25 is formed whollyin the bottom portion of the door and noty in the body portion 2'? ofthe housing. The fuse link 28 extendsaround the bottom edge of the tubeand around the barrier, the barrier freely yicldingand permitting thecomplete sealing of the lower opening 25.

In the form of the invention shown in Figure 4, the shield or barrier 29carried by the fuse cartridge 4 is provided with a cylindrical portion30 and with an upper ange or inner flange 3l. The opening 32 in thebottom of the door 33 is cylindrical and has a fiat upper face againstwhich the flange 3l contacts. In this case also the body portion 34 doesnot form a vportion of the opening 32, the opening being formed wholly4in the door, as stated. The fuse link 35 is looped around the lowerportion of Ythe fuse tube and around the barrier or shield 29.

Inasmuch as this fuse link is of very freely yielding or deformablematerial, it is clear that it will conform itself. to the outline of theopening and barrier, as shown` in Figure 4, and thus a substantiallytight joint is maintained, thereby preventing the entrance of gases intothe housing or box. l

From actual tests with this device, it has been found that there is agreat increase in the rupturing capacity without arcing within thevinternal contacts within the housing, as the highly conducting gasesformed at the time of the expulsion of the fuse link are prevented iromreversing their iiow and entering the housing.

Further, it will be seen that the device in each of its several forms isvery simple to construct and does not materially add to the cost of theconstruction of the cutout type of expulsion fuse, as the insulatingbarrier or shield at the lower end of the fuse tube is small and easilyapplied. It may be as freely handled as any'other type of expulsionfuseand may be renewed and replaced .with the same facility as the usualtypes of expulsion fuses.

Although this invention has been described in considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the invention may be variously embodied and isto be interpreted as claimed.

We claim:

l. Anexpulsion type fuse comprising a housing having a body portion anda door hinged thereto adjacent the lower end, said housing having anopening'adjacent its lower end, an expulsion fuse cartridge carried bysaid door, said housing and said fuse cartridge being provided withcooperating contacts, a barrier carried at the lower end of saidcartridge and forming the bottom of said cartridge and substantiallysealing the opening within said housing, and a fuse link extendingbetween the contacts of said fuse cartridge and looped around the lowerend of said fuse cartridge and said barrier.

2. An explusion type fuse comprising a housing having a body portion anda door hinged thereto,

said door and said body portion having an opening formed jointly thereinand adjacent the lower portion of said housing, a fuse cartridgeremovably carried by said door and having an open lower end locatedwithin said opening and spaced a slight distance upwardly from thebottom of said opening, a barrier carried adjacent the lower end of saidfuse cartridge, upper and lower contacts carried by said cartridge, alink joining said contacts and extending through said cartridge andlooped around the lower end of said cartridge and said barrier,` andspring terminal contacts carried within said housing and adapted toengage the contacts oiisaid cartridge.

3. An expulsion type fuse comprising a housing having a body portion anda door, said door hav. ing an opening formed in the lower portionthereof a fuse cartridge carried by said door and having a lower openend, a yieldingV barrier carried by said fuse cartridge adjacent saidlower open end and sealing the opening within said door, said fusecartridge having contacts, a link located within said cartridge andjoining said contacts and looped around the lower end of said cartridgeand said barrier, and stationary contacts carried by said body portionfor engagement with the contacts of said cartridge.

- 4. An expulsion type fuse comprising a housing having a body portionand a door hinged thereto, said door having a tapered opening adjacentits lower end, a fuse cartridge having a lower open end, a yieldingbarrier carried by the lower end of said fuse cartridge, said barrierbeing tapered and sealing within the tapered opening within said door,contacts carried by said fuse cartridge, a link located within saidcartridge and looped around the lower end thereof and around saidbarrier and joining said contacts, and stationary contacts carried bysaid body portion and adapted to engage the contacts of said cartridge.

5. An expulsion type fuse comprising a housing having a body portion anda door, said door having an openingin its lower end, a fuse cartridgecarried by said door and provided with upper and lower contacts, saidfuse cartridge having an open lower end, a barrier carried by the lowerend of said vcartridge and fitting within the opening within said door,said barrier having a fiange contacting with the inner side of said dooradjacent said opening, a fuse link within said cartridge joining saidupper and lower contacts and looped around the lower end of saidcartridge and said barrier, and stationary contacts carried by said bodyportion and adapted to engage the contacts of said cartridge.

ALWIN G. STEINMAYER. WILLIAM D. KYLE.

